0:08Skip to 0 minutes and 8 secondsWelcome to week one. We're starting our course by perhaps asking the most obvious question - "What is addiction?" We're looking at a definition of addiction, and discussing how we define this phenomenon. We'll commence our explanation of the biological underpinnings of addiction too. In a way, we're commencing our own journey. I'm going to start the ball rolling by considering the question, "What is addiction?" In this lecture, I'll discuss how addiction doesn't respect your background, whether you're rich or poor, privileged, educated, male or female. But it does happen for a reason. Addiction is functional. It serves a purpose. The most obvious and fundamental initial experience is that the drug feels good.

0:58Skip to 0 minutes and 58 secondsNo matter what the mechanism of action, all drugs of abuse share some common features, perhaps the most important of which is that they increase activity in the reward centre, the pleasure centre of our brain. I think it's very important to remember here, though, that not everyone who uses a drug will become addicted. Indeed, many people use drugs recreationally and don't go on to develop addiction or experience some of the more serious harms. However, for those for whom addiction does develop, then the journey back to abstinence is a very difficult and sometimes a very long journey.

1:36Skip to 1 minute and 36 secondsThe hallmark of addiction is that it takes precedence over other needs and we spend more and more time obtaining a drug or engaging in our addiction, using the drug, and then recovering from its effects, so much so that we have less time available to focus on other important tasks in our daily life. For me, addiction is also characterised by compulsion, those feelings of craving and desire that build up whenever we just try to say no. In the next lectures, we then go on to look more closely at those structures of the brain that are most important for developing addiction. I'll describe how information is transmitted in the brain, from cell to cell, neuron to neuron, a process we call neurotransmission.

2:25Skip to 2 minutes and 25 secondsAnd I'll describe how drugs can affect any of the steps of neurotransmission, how drugs either mimic the brain's natural chemical messengers, or, by causing the cells to release abnormally large amounts of these chemical messengers, they prevent the system from being closed down. Finally, this week I'm joined by Dr Claire Troakes. Claire is the coordinator of the MRC Brain Bank at the Institute of Psychiatry. The Brain Bank stores human brains and spinal cord tissue for scientists to use in their research. Claire will describe her work in the Brain Bank. Claire's also, though, an expert in neuroanatomy. She'll show us with some real human brains the reward pathway and the structures of the brain that are involved in addiction.

3:15Skip to 3 minutes and 15 secondsShe'll describe how these structures interact with the environment to cause addiction. So in total, Claire and I will be describing how the brain changes as addiction develops, and how once addiction has developed, it takes the brain a very long time to re-adapt to life without the drug, how it takes the brain a very long time to re-adapt to life without an addiction. We close this week with a research showcase from Claire. Claire will describe the Brain Bank to us, and she'll describe some of the research that she's currently involved with. I hope you find this course, and this week in particular, to be thought-provoking, challenging, and I hope an enjoyable journey. Thanks for your time, and let's get started.

Week 1 overview

Welcome to week 1: ‘The journey to addiction: Part 1’.

Over these first two weeks, we will explore some of the important foundations to our understanding of addiction. In this first week, our focus is on the diagnostic criteria of addiction and its relevant biological mechanisms.